It is perhaps a fitting tribute to racial co-operation. However, the decision to outsource to China the carving of a new national memorial to Martin Luther King has raised eyebrows in the United States.

The 30ft-tall statue, which forms the centrepiece of a $120 million (£73 million), four-acre memorial to Dr King, opened to the public on Monday on the National Mall in Washington. It is the only memorial on the Mall that does not honour a president or fallen soldiers.

Standing in the shadow of the Washington Monument, the statue shows Dr King emerging from a mountain of Chinese granite with his arms crossed and is called The Stone of Hope.

However, there has been controversy over the choice of Lei Yixin, a 57-year-old master sculptor from Changsha in Hunan province, to carry out the work. Critics have openly asked why a black, or at least an American, artist was not chosen and even remarked that Dr King appears slightly Asian in Mr Lei's rendering.